With the unpredictable depletion of fossil fuels, such as coal and petroleum, even though oil fields are being continuously discovered, clean and renewable energy resources show growing significance to human society. One of major goals of materials scientists is to develop some typical kinds of materials of high conversional efficiency, from solar to renewable energy, as well as favorable low cost for manufacture, which will play a role in producing renewable energy. The family of tin sulfides SnxSy (SnS, Sn2S3, and SnS2) has been predicted to be a competitor for the next-generation photoelectrochemical (PEC) materials with high solar conversion properties, especially in water splitting field. In this work, we picked up tin sulfides SnxSy as our reactant (precursor), which can be extracted from natural ores, such as Herzenbergite ((Sn, Pb) SnS2) and may lead to industrial benefits. The tin sulfides SnxSy thin films were prepared on Mo-coated soda-lime glass (SLG) substrates through thermal evaporation of SnS powder sources, followed by thermal annealing under Ar atmosphere or in the presence of H2S. The three-electrode configuration was employed to characterize the PEC properties of the prepared tin sulfides SnxSy thin films for PEC water splitting under simulated sunlight. The results show that high purity of SnS, Sn2S3, and SnS2 can be obtained through controlling the annealing temperature and H2S atmosphere. The obtained SnS and Sn2S3 thin films exhibit p-type conductivity, while the SnS2 shows the n-type conductivity. The PEC activities of the SnS, Sn2S3, and SnS2 electrodes were drastically enhanced through surface modification and co-catalyst loading. The effects of annealing temperature, H2S atmosphere, and surface modification on the phases, morphologies, and PEC properties of the tin sulfides SnxSy thin films were discussed. Our results suggest that feasibility of controlled synthesis of tin sulfides SnxSy (i.e., SnS, Sn2S3, and SnS2) using thermal evaporation from SnS powder precursor combined with thermal annealing. Furthermore, our results indicate that SnxSy coupled with suitable surface modification could be used as promising photoelectrodes in PEC water splitting for solar energy storage.

Controlled synthesis of earth-abundant tin sulfides SnxSy thin films for photoelectrochemical water splitting

255th National Meeting (2018)

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